1. Field of the Invention
The present invention relates to a method for producing mixed-oxide nuclear fuel pellets of uranium dioxide (UO.sub.2+x) and plutonium dioxide (PuO.sub.2) soluble in nitric acid.
2. Background of the Invention
It was known to make fuel pellets by milling the powder mixture with a PuO.sub.2 -content of up to 50% in mills wihin glove boxes and by subsequent granulating, pressing and sintering. The requirement of solubility of nuclear fuel pellets results from the necessity of reprocessing burned-up nuclear fuels and the recovery, connected therewith, of most valuable raw materials. This requirement in itself is not new: reference is made to German Published Non-Prosecuted Application No. 28 33 054. According to the method proposed there, the formation of the mixed crystals, as a prerequisite for the solubility, is achieved by repeated milling of the radiotoxic material. Apart from the increased radiation exposure, connected therewith, of the operating personnel, which cannot be avoided completely even when working with so-called shielded glove boxes, this method is relatively cumbersome. The dust production in milling or when emptying the mills is also a disadvantage, since the dust deposits in the closed-off glove boxes on all surfaces and thus must be removed again by decontamination.